package com.mming.sso.util;

import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTVerificationException;
import com.auth0.jwt.interfaces.DecodedJWT;
import lombok.extern.slf4j.Slf4j;

import java.util.Date;

@Slf4j
public class TokenUtil {
    // 过期时间两小时
    public static final int EXPIRE_TIME = 3 * 60 * 60 * 1000;
    //token secret
    public static final String SECRET = "mming3";
    //redis token key prefix
    public static final String KEY_PREFIX = "_sso_login_status_of_";

    /**
     * 生成签名,5min后过期
     *
     * @param username 用户名
     * @param secret   用户的密码
     * @return 加密的token
     */
    public static String sign(String username, String secret) {
        Date date = new Date(System.currentTimeMillis() + EXPIRE_TIME);
        Algorithm algorithm = Algorithm.HMAC256(secret);
        // 附带username信息
        return JWT.create()
                .withClaim("username", username)
                .withExpiresAt(date)
                .sign(algorithm);
    }

    /**
     * 校验token是否正确
     *
     * @param token  密钥
     * @param secret 用户的密码
     * @return 是否正确
     */
    public static boolean verify(String token, String username, String secret) {
        Algorithm algorithm = Algorithm.HMAC256(secret);
        JWTVerifier verifier = JWT.require(algorithm)
                .withClaim("username", username)
                .build();
        try {
            DecodedJWT jwt = verifier.verify(token);
            log.info(username + " verify success in " + TimeUtil.getDatetime());
        } catch (JWTVerificationException e) {
            log.info(username + " verify fail in " + TimeUtil.getDatetime() + " because " + e.getMessage());
            return false;
        }
        return true;
    }

    /**
     * 获得token中的信息无需secret解密也能获得
     *
     * @return token中包含的用户名
     */
    public static String getUsername(String token) {
        DecodedJWT jwt = JWT.decode(token);
        return jwt.getClaim("username").asString();
    }

    public static String generateLoginKey(String username) {
        return SECRET + KEY_PREFIX + username;
    }
}
